This invention relates to hauling systems, and more specifically to systems for hauling loose bulk material at a construction site using a self-propelled vehicle ordinarily found on the site that can be used to propel a trailer that is not self-propelled. The self-propelled vehicle can be attached to or disconnected from the trailer by the driver of the self-propelled vehicle, without assistance and without exiting from the cab of the self-propelled vehicle.
The movement of materials, gravel, dirt, and the like at construction sites is a common problem. Common solutions involve the use of special hauling vehicles such as self-propelled dump trucks, to complement a front wheel loader or steam shovel that is used to excavate and to lift and load debris. These solutions work well, but require the capital cost of a second heavy duty vehicle, plus the operation cost of a second driver, in addition to what is required for the loader or steam shovel.
Another common solution is to load debris into a dumpster. This requires the hiring of a waste service. Also, the dumpster is stationary on the site. This solution is not well suited to moving material around at a site, as is often required.
Generally, a wide variety of hauling systems are well known, ranging from railroad trains to pickup trucks, tractor trailer trucks, and sophisticated refuse pick up and hauling trucks.
In hauling systems involving a tractor and a trailer, the tractor and the trailer should connect with relative ease. In existing hauling systems, it is often necessary for the operator of the tractor to rely on an observer to direct the tractor into alignment with the trailer, so that the two vehicles can be connected. Even where some form of alignment mechanism is used that is visible from the cab of the tractor, so as to permit the operator to align the vehicles alone, as in Miller, U.S. Pat. No. 4,313,264; Surer, U.S. Pat. No. 4,723,788; or Sand, U.S. Pat. No. 4,666,176, it is generally necessary for the operator to exit from the tractor in order to physically connect the tractor to the trailer. In those systems that permit the vehicles to be connected without the operator exiting from the tractor, such as Cook, U.S. Pat. No. 4,560,183, the operator must still exit from the tractor in order to dismantle the connecting mechanism once the vehicles are connected, in order to permit complete freedom of movement of the tractor and trailer in combination.
Another deficiency in existing systems, such as described in Cook, is that they will not function if the rear of the tractor and front of the trailer are out of vertical alignment. This will be the norm with many trailers, in which the front end leans against the ground unless jacked up. It also will occur, for example, if the trailer holds an uneven load that causes the front of the trailer to sink relative to the rear of the trailer, and hence come out of vertical alignment with the rear of the tractor. None of the existing systems provide a means for adjusting the vertical position of the trailer from within the tractor, when the trailer is not vertically aligned with the tractor.
In other existing systems, such as Sheine, U.S. Pat. No. 4,133,552, in addition to requiring an operator to leave the tractor, the mechanism that permits the two vehicles to be connected requires extensive connections between the two vehicles that must be completed by the operator or a second individual. This is inconvenient and inefficient if the vehicles are to be connected and disconnected frequently.
While these prior art hauling systems work well for certain applications, they are not easily used or economical for hauling debris and loose bulk material around a construction site, particularly a small site. They often require a specialized propelled vehicle that is used only for hauling and an operator for that vehicle. The prior art solutions also usually require the operator or an assistant to spend time outside the vehicle, which presents clear safety problems.
It is therefore an object of this invention to provide a hauling system in which a self-propelled vehicle can be connected to a trailer that is not self-propelled by a single operator who does not have to leave the self-propelled vehicle to align and connect or disconnect the vehicles.
It is also an object of this invention to provide a hauling system in which a self-propelled vehicle can be connected to a trailer that is not self-propelled in less time than has previously been necessary, and to permit a hauling operation to be performed more quickly.
It is a further object of this invention to provide a hauling system in which the functions of two separate vehicles can be utilized by a single operator positioned in one of the vehicles.
It is another object of this invention to provide a hauling system in which functions that previously required the use of two self-propelled vehicles can be utilized through the use of one self-propelled vehicle and a second vehicle that is not self-propelled and therefore does not require an engine to propel it and requires a significantly lower capital and operating expense.
It is yet another object of this invention to provide a hauling system in which two vehicles can be coupled, and operations involving the second vehicle controlled, without the need for additional connections, such as electrical, hydraulic, or pneumatic lines, running from the first vehicle to the second, other than what is required to keep the second vehicle secured to the first.
It is still another object of this invention to provide a hauling system that requires the use of one self-propelled vehicle and one vehicle that is not self-propelled, where both vehicles are easily modified versions of standard vehicles, and the self-propelled vehicle is of a type that is commonly utilized at construction sites.